Nicole Stadie

Unambiguous generalization effects after treatment of non-canonical sentence production in German agrammatism

Agrammatism is-among others, characterized by a deficit in producing grammatical structures. Of specific difficulty is the utilization of complex, non-canonical sentence structures (e.g. object-questions, passives, object-clefts). Several studies have documented positive effects when applying a specific treatment protocol in terms of increasingly correct production of target complex sentence structures with some variance in generalization patterns noted across individuals. The objective of this intervention study was to evaluate an intervention program focussing on the production of non-canonical sentences. Hypotheses about the occurrence of treatment effects were formulated on the basis of syntactic complexity, referring to the amount of syntactic phrase structures necessary to generate specific German sentence structures. A multiple single case study with seven agrammatic participants was applied, each participant receiving training in the production of object-relative-clauses and who-questions. The investigation was designed to unambiguously evaluate for each individual, structure specific and generalized learning effects with respect to the production of object-relative-clauses, who-questions and passive sentences. Results showed significant improvements for all sentences types. This outcome is considered within methodological issues of treatment studies. Theoretical and clinical implications are discussed.

Evaluation of lexically and nonlexically based reading treatment in a deep dyslexic

The aim of the single case study was to evaluate two different treatment procedures to improve reading skills with a German-speaking deep dyslexic. Generally, in treatment studies for deep dyslexia, retraining of grapheme–phoneme correspondences is described, but hardly any treatment focuses on reactivating residual functions of the semantic–lexical route. This strategy was explored here with an experimentally presented priming paradigm, to implicitly strengthen residual skills of lexical access with semantically/phonologically related primes (lexically based treatment). In contrast, grapheme–phoneme associations and blending were explicitly relearned during a nonlexically based treatment. Stimuli were controlled for part of speech, word length, and frequency. A cross-over design to identify item- and treatment-specific effects for both procedures was applied. Results indicate positive outcomes with respect to treatment-specific effects for both procedures, generalization to untrained items, and a transfer task after the nonlexically based procedure. All effects remained stable in the follow-up assessment. Implications for theoretically/empirically generated expectations about treatment outcomes are discussed.

Training-induced improvement of noncanonical sentence production does not generalize to comprehension: evidence for modality-specific processes

The presence or absence of generalization after treatment can provide important insights into the functional relationship between cognitive processes. The aim of the present study was to investigate the relationship between the cognitive processes that underlie sentence comprehension and production in aphasia. Using data from seven participants who took part in a case-series intervention study that focused on noncanonical sentence production [Stadie et al. (2008). Unambiguous generalization effects after treatment of noncanonical sentence production in German agrammatism. Brain and Language, 104, 211–229], we identified patterns of impairments and generalization effects for the two modalities. Results showed (a) dissociations between sentence structures and modalities before treatment, (b) an absence of cross-modal generalization from production to comprehension after treatment, and (c), a co-occurrence of spared comprehension before treatment and generalization across sentence structures within production after treatment. These findings are in line with the assumption of modality-specific, but interacting, cognitive processes in sentence comprehension and production. More specifically, this interaction is assumed to be unidirectional, allowing treatment-induced improvements in production to be supported by preserved comprehension.

Does training-induced improvement of noncanonical sentence production in agrammatic aphasia generalize to comprehension? A multiple single case study

Despite this, none of the participants showed any improvements in comprehension of the same sentence structure. After production treatment, each participant performed within the individual pre-treatment chance level in comprehension. DISCUSSION The finding that none of the participants improved in comprehension of sentences successfully trained in production adds to the evidence from a previous study in which training of noncanonical sentence production did not generalize to comprehension (Jacobs & Thompson, 2000).

Feature dissimilarities in the processing of German relative clauses in aphasia

Abstract The cross-linguistic finding of greater demands in processing object relatives as compared to subject relatives in individuals with aphasia and non-brain-damaged speakers has been explained within the Relativized Minimality approach. Based on this account, the asymmetry is attributed to an element intervening between the moved element and its extraction site in object relatives, but not in subject relatives. Moreover, it has been proposed that processing of object relatives is facilitated if the intervening and the moved elements differ in their internal feature structure. The present study investigates these predictions in German-speaking individuals with aphasia and a group of control participants by combining the visual world eye-tracking methodology with an auditory referent-identification task. Our results provide support for the Relativized Minimality approach. Particularly, the degree of featural distinctness was shown to modulate the occurrence of the effects in aphasia. We claim that, due to reduced processing capacities, individuals with aphasia need a higher degree of featural dissimilarity to distinguish the moved from the intervening element in object relatives to overcome their syntactic deficit.

Treatment of sentence comprehension and production in aphasia: is there cross-modal generalisation?

ABSTRACT Exploring generalisation following treatment of language deficits in aphasia can provide insights into the functional relation of the cognitive processing systems involved. In the present study, we first review treatment outcomes of interventions targeting sentence processing deficits and, second report a treatment study examining the occurrence of practice effects and generalisation in sentence comprehension and production. In order to explore the potential linkage between processing systems involved in comprehending and producing sentences, we investigated whether improvements generalise within (i.e., uni-modal generalisation in comprehension or in production) and/or across modalities (i.e., cross-modal generalisation from comprehension to production or vice versa). Two individuals with aphasia displaying co-occurring deficits in sentence comprehension and production were trained on complex, non-canonical sentences in both modalities. Two evidence-based treatment protocols were applied in a crossover intervention study with sequence of treatment phases being randomly allocated. Both participants benefited significantly from treatment, leading to uni-modal generalisation in both comprehension and production. However, cross-modal generalisation did not occur. The magnitude of uni-modal generalisation in sentence production was related to participants’ sentence comprehension performance prior to treatment. These findings support the assumption of modality-specific sub-systems for sentence comprehension and production, being linked uni-directionally from comprehension to production.